The research proposed is primarily aimed at elucidating those forces which are important in stabilizing the secondary and tertiary structures of nucleic acids and those molecular interactions which underlie codon-anticodon recognition processes and the degeneracy of the genetic code. Experiments have been undertaken to ascertain whether tautomerism of nucleic acid bases can provide for an important source of spontaneous mutations, and whether it can allow for alternate base-pairing schemes, in addition to the well-known Watson Crick complementary G-C and A-T (or A-U) base pairs, for the stabilization of RNA structures, and for codon-anticodon recognition. The conformational properties of oligonucleotides and polynucleotides are also being investigated by high resolution proton magnetic resonance spectroscopy to characterize the base stacking interactions and to establish their relative importance in determining the secondary and tertiary structures of nucleic acids. An investigation of the interaction of ATP with phospholipid bilayer vesicles is also proposed. These studies are designed to determine the mode of binding of the ATP to membrane vesicles and to ascertain whether an asymmetrical distribution of divalent ions on the two sides of a bilayer membrane can lead to asymmetric binding of ATP on the outer ad inner halves of the bilayer, and hence result in an asymmetry in the membrane.